While electricity has mostly been restored to 4,000 customers affected during Saturday's widespread outage, the National Weather Service issued an excessive heat warning for the five boroughs that lasted from noon Sunday to around 8 that evening.

With the hottest conditions occurring during the afternoon, Staten Islanders did their best to keep cool. With the heat and humidity, it felt more like 105 degrees. The National Weather Service urged New Yorkers to take extra precautions, especially those who planned on being outdoors.

AccuWeather's forecast called for a 70 percent chance of thunderstorms Sunday night, which should have dissipated into Monday morning. The weather service predicts scattered thunderstorms for the early part of the week, with highs ranging from the upper 80s to low 90s.

Despite the heat, power outages remained minimal throughout Sunday, according to the Con Edison website.

Throughout Saturday night and into Sunday morning, some 1,800 Island customers were without power from New Dorp to Clifton, with large swaths of Dongan Hills, South Beach and Midland Beach included in the affected areas. At its peak, over 4,000 customers lost electricity.

There was no evidence that these outages were a result of the weekend's extreme heat, according to Con Edison spokesman, Bob McGee. He said additional tests would have to be conducted on the burned-out cables responsible, in order to determine how much the heat played a role.

The actual cause was an overnight manhole fire near the Fox Hills substation. The blaze caused Con Edison to reduce voltage to the several neighborhoods early Saturday morning. The manhole fire, at the intersection of Clifton Avenue and Colton Street, took out three feeders, causing major outages, said McGee.

"Essentially everything has devolved since then in terms of trying to implement repairs."